When Katherine Grainger broke down in tears in Beijing after being pipped for gold yet again, it was unclear whether the three-time Olympic silver-medallist would have the resolve to have one more crack.

But the desire to finish what she had started 15 years before drove her onto the road to London, where, at the fourth time of asking, the 36-year-old from Glasgow claimed the gold medal she craved.

Together with Anna Watkins, Grainger destroyed the field in the final of the women's double sculls at Eton Dorney with a performance as dominant as each of the 23 other races they have entered since they began their unbeaten partnership in 2010.

Born in Glasgow, Grainger did not take up rowing until she went to university in Edinburgh and began studying law. Within four years, she was competing internationally in the under-23 World Championships, winning gold before graduating to the senior team.

Her breakthrough came in 2000, when she took a surprise silver in the women's quad at the Sydney Olympics, having finished a distant seventh in the World Championships a year before.

Another silver followed in Athens with Cath Bishop as the pair surged from fourth to second in the closing stages behind the dominant Romanian crew.

Together with Annie Vernon, Debbie Flood and Frances Houghton, Grainger rowed her way into the final with ease and led with 200m to go before China overhauled them.

A third silver was put around her neck as she wept uncontrollably during the medal ceremony, raising questions as to whether that was to be the end of her Olympic career.

But she returned to rowing a year later, this time in the single, and decided to combine her training with her homicide studies for a PhD following the completion of a Masters in medical law and medical ethics.

The extra work appeared to have little effect on her results as she rowed to silver in the World Championships - but it was in 2010 that everything changed.

Katherine Grainger factfile

Born: 12 November 1975

Birthplace: Glasgow

Lives: Maidenhead

Event: Double sculls

Coach: Paul Thompson

Partnered with Watkins in a relationship that Grainger says "just worked from the start", a legend was born. The duo have gone on to win every race they have entered, including two World Championship gold medals - bringing Grainger's total to six - and six World Cup golds.

As a result, Grainger arrived at the London Olympics as the outright favourite for the first time in her career.

She then delivered on what was expected for the fourth Games in a row to become the Sir Steve Redgrave of British female rowing. Should a damehood follow, few would be more deserving.